Sheet discharge device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9580267-B2
Application number	US-201514666102-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Mar 26, 2014
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

In a post-processing device (sheet discharge device), a pile thickness calculating section calculates, from a type and the number of paper sheets discharged through a sheet output port, a thickness of a pile, at its leading end, of sets of paper sheets on a sheet output tray (piling section), calculates a thickness of the pile, at its trailing end, of sets of paper sheets on the sheet output tray from an amount of movement of a lifting section, and calculates an angle of inclination of the uppermost set of paper sheets in the pile from the thicknesses of the pile at its leading and trailing ends, a height of inclination of the sheet output tray, and a length of the paper sheets. The control section controls the sheet discharge section to change a manner of discharging a subsequent set of paper sheets according to the calculated angle of inclination.

First claim

What is claimed is:

1. A sheet discharge device comprising:
a sheet discharge section configured to discharge a set of paper sheets through a sheet output port;
a stapler configured to, before the set of paper sheets is discharged through the sheet output port, apply a staple to a predetermined location on a trailing end portion of the set of paper sheets in a direction of discharge thereof;
a piling section capable of being piled with sets of paper sheets discharged through the sheet output port, while a pile of the sets of paper sheets on the piling section being inclined so that a trailing end of the pile of the sets of paper sheets in the direction of discharge is located below a leading end thereof in the direction of discharge;
a lifting section configured to vertically lift and lower the piling section toward and away from the sheet output port;
a top surface detecting section configured to detect that a trailing end, in the direction of discharge, of a top surface of the pile of the sets of paper sheets on the piling section capable of being lifted and lowered by the lifting section has reached a predetermined sheet receiving height;
a discharge detecting section configured to detect that the set of paper sheets has been discharged through the sheet output port to the piling section;
a control section configured to, when the discharge detecting section detects that the set of paper sheets has been discharged to the piling section, allow the lifting section to lower the piling section by a certain amount and then lift the piling section from a lowered position where the piling section lowered by the certain amount is located to a position where the trailing end, in the direction of discharge, of the top surface of the pile of the sets of paper sheets on the piling section is detected by the top surface detecting section; and
a pile thickness calculating section configured to calculate, from a type and the number of paper sheets constituting each of the sets of paper sheets discharged through the sheet output port and the number of the discharged sets of paper sheets, a thickness of the pile, at the leading end thereof in the direction of discharge, of the sets of paper sheets on the piling section, calculate a thickness of the pile, at the trailing end thereof in the direction of discharge, of the sets of paper sheets on the piling section from an amount of movement of the piling section from the lowered position to the position where the trailing end of the top surface of the pile in the direction of discharge is detected by the top surface detecting section, and calculate an angle of inclination of the uppermost of the sets of paper sheets piled on the piling section with respect to a horizontal plane from the calculated thicknesses of the pile, at the leading and trailing ends in the direction of discharge, of the sets of paper sheets on the piling section, a height of inclination of the piling section, and a length of the paper sheets constituting the pile of the sets of paper sheets,
wherein the control section is further configured to control the sheet discharge section to change a manner of discharging a subsequent set of paper sheets according to the calculated angle of inclination.

2. The sheet discharge device according to claim 1 , wherein the pile thickness calculating section is configured to calculate the angle of inclination according to the formula α=arcsin((Ha+X−Hb)/L) where α represents the angle of inclination, Ha represents a thickness of the pile, at the leading end thereof in the direction of discharge, of the sets of paper sheets on the piling section, X represents a height from a lowermost end to an uppermost end of a piling surface of the piling section on which the paper sheets are piled, Hb represents a thickness of the pile, at the trailing end thereof in the direction of discharge, of the sets of paper sheets on the piling section, and L represent a length of the paper sheet in the direction of discharge.

3. The sheet discharge device according to claim 1 , wherein when the angle of inclination is smaller than a predetermined angle, the control section allows the sheet discharge section to discharge each subsequent stapled set of paper sheets through the sheet output port to a location offset in the direction of discharge or a direction perpendicular to the direction of discharge at each time of discharge of the stapled set of paper sheets.

4. The sheet discharge device according to claim 1 , wherein when the angle of inclination is smaller than a predetermined angle, the control section allows the sheet discharge section to discharge subsequent stapled sets of paper sheets, face up and face down alternately every predetermined number of sets, through the sheet output port.

5. The sheet discharge device according to claim 1 , wherein the pile thickness calculating section is configured to save, in a memory as needed, the thicknesses of the pile, at the leading and trailing ends thereof in the direction of discharge, of the sets of paper sheets on the piling section to correlate the thicknesses with each other and configured to, when some of the sets of paper sheets piled on the piling section is removed so that the thickness of the pile at the trailing end thereof in the direction of discharge decreases, read the thickness of the pile at the leading end thereof in the direction of discharge, the thickness being correlated with the decreased thickness of the pile at the trailing end thereof in the direction of discharge, from the memory and update the calculated value of the thickness of the pile, at the leading end thereof in the direction of discharge, of the sets of paper sheets on the piling section to the read thickness.

6. The sheet discharge device according to claim 1 , wherein when the angle of inclination becomes nearly horizontal, the control section allows the sheet discharge section to stop discharging a next paper sheet to the piling section.

7. An image forming apparatus comprising:
a sheet discharge device;
an image forming section configured to form an image on a paper sheet; and
a notifying section configured to give notice to a user,
wherein the sheet discharge device comprises:
a sheet discharge section configured to discharge a set of paper sheets through a sheet output port;
a stapler configured to, before the set of paper sheets is discharged through the sheet output port, apply a staple to a predetermined location on a trailing end portion of the set of paper sheets in a direction of discharge thereof;
a piling section capable of being piled with sets of paper sheets discharged through the sheet output port, while a pile of the sets of paper sheets on the piling section being inclined so that a trailing end of the pile of the sets of paper sheets in the direction of discharge is located below a leading end thereof in the direction of discharge;
a lifting section configured to vertically lift and lower the piling section toward and away from the sheet output port;
a top surface detecting section configured to detect that a trailing end, in the direction of discharge, of a top surface of the pile of the sets of paper sheets on the piling section capable of being lifted and lowered by the lifting section has reached a predetermined sheet receiving height;
a discharge detecting section configured to detect that the set of paper sheets has been discharged through the sheet output port to the piling section;
a control section configured to, when the discharge detecting section detects that the set of paper sheets has been discharged to the piling section, allow the lifting section to lower the piling section by a certain amount and then lift the piling section from a lowered position where the piling section lowered by t

Assignees

• Kyocera Document Solutions Inc

Inventors

• Noda Tatsuo
• Nagira Jiro

Classifications

• B65H43/06

  detecting, or responding to, completion of pile (B65H43/08 takes precedence) · CPC title

• B65H2511/13

  Thickness · CPC title

• B65H2511/21

  Angle · CPC title

• B65H37/04

  for securing together articles or webs, e.g. by adhesive, stitching or stapling (adhering replacement to expiring web during change of web roll B65H19/18) · CPC title

• B65H31/04 Primary

  with movable end support arranged to recede as pile accumulates · CPC title